WO2017154439A1 - Method for manufacturing polymer, method for manufacturing negative-type photosensitive resin composition, method for manufacturing resin film, method for manufacturing electronic device, and polymer - Google Patents

Abstract

This method for manufacturing a polymer includes a step for preparing a precursor polymer including structural units represented by formula (1a), a step for applying water or an alcohol represented by the formula R₁-OH (where R₁ is a C1-18 organic group) to the precursor polymer including structural units represented by formula (1a) to cause ring opening of maleic anhydride portions of the structural units represented by formula (1a) and generating a carboxyl group or a salt thereof in the precursor polymer, and a step for reacting a compound provided with an epoxy group represented by formula (3) with the precursor polymer in which maleic anhydride portions are ring-opened. (In formula (3), R₂ represents a C2-18 organic group and has a carbon-carbon double bond in the structure thereof.)

Description

Method for producing polymer, method for producing negative photosensitive resin composition, method for producing resin film, method for producing electronic device, and polymer

The present invention relates to a method for producing a polymer, a method for producing a negative photosensitive resin composition, a method for producing a resin film, a method for producing an electronic device, and a polymer.

Conventionally, studies on polymers (polymers) having structural units derived from maleic anhydride have been intensively conducted.
When this maleic anhydride is reacted with, for example, alcohols, the site derived from the acid anhydride is opened to give a site having an ester bond and a site having a carboxyl group. As described above, there is also a background that chemical conversion can be easily performed. In particular, in the field of photosensitive resins, applied development has been made for various polymers having structural units derived from maleic anhydride. .

In this connection, Patent Document 1 discloses that at least a part of an acid anhydride group in a copolymer mainly composed of indene and maleic anhydride is unsaturated alcohol. A photosensitive resin obtained by esterification is disclosed.
According to this document, this photosensitive resin is considered to have high heat resistance. Further, it is said that this photosensitive resin can be developed into a solder-resist resist, an etching resist, a plating resist, and a pattern forming material at the time of manufacturing a semiconductor element by itself or by using other components and compositions.

Japanese Patent Laid-Open No. 5-134413

However, due to recent demands for higher density electronic devices and more efficient electronic device manufacturing processes, photosensitive resin compositions are required to be reliably cured with a lower exposure amount. Therefore, there is a great demand for the polymer constituting the photosensitive resin composition to have better curing performance and the like.

In view of such circumstances, the present invention provides a polymer that can be cured at a low exposure amount and is useful for constituting a negative photosensitive resin composition or the like.

According to the present invention,
Preparing a precursor polymer containing a structural unit represented by the following formula (1a);
Alcohol represented by R ₁ —OH (where R ₁ is an organic group having 1 to 18 carbon atoms) or water is allowed to act on the precursor polymer containing the structural unit represented by the formula (1a). Opening the maleic anhydride site of the structural unit represented by formula (1a) to form a carboxyl group or a salt thereof in the precursor polymer,
Reacting a compound having an epoxy group represented by the formula (3) with the precursor polymer having a ring opening of a maleic anhydride site;
A process for producing a polymer comprising is provided.

(In Formula (3), R ₂ is an organic group having 2 to 18 carbon atoms, and has a carbon-carbon double bond in its structure.)

Moreover, according to the present invention,
There is provided a method for producing a negative photosensitive resin composition, comprising a step of obtaining a polymer by the method for producing a polymer and further incorporating a photo radical generator.

Moreover, according to the present invention,
There is provided a method for producing a resin film, comprising the steps of obtaining a negative photosensitive resin composition by the method for producing a negative photosensitive resin composition and further curing the negative photosensitive resin composition. .

Moreover, according to the present invention,
There is provided an electronic device manufacturing method including the above-described resin film manufacturing method in the process.

Furthermore, according to the present invention,
A polymer containing a structural unit represented by the following formula (1) is provided.

(In Formula (1), R ₁ is an organic group having 1 to 18 carbon atoms. R ₂ is an organic group having 2 to 18 carbon atoms, and has a carbon-carbon double bond in the structure thereof.)

In the polymer production method of the present invention, a specific compound having an epoxy group is allowed to act on a functional group such as a carboxyl group derived from a structural unit derived from maleic anhydride. Although it is not certain, it is considered that a functional group capable of improving the sensitivity can be generated in the polymer structure by acting such a specific compound. Further, as a result, it is considered that curing can be dramatically accelerated when the photosensitive resin composition containing the obtained polymer is exposed.
From this, it can be said that the polymer obtained by the production method of the present invention can be cured at a low exposure amount and is useful for constituting a negative photosensitive resin composition and the like.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is sectional drawing which shows an example of the electronic device which concerns on this embodiment.

Hereinafter, embodiments will be described with reference to the drawings as appropriate. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate. Further, “˜” represents the following from the above unless otherwise specified.

[Method for producing polymer]
First, the manufacturing method of the polymer of this embodiment is demonstrated.
The method for producing a polymer of the present embodiment comprises the following steps (steps (i) to (iii)).
(I) Step of preparing a precursor polymer containing a structural unit represented by the following formula (1a) (ii) A precursor polymer containing a structural unit represented by the formula (1a) is represented by R ₁ —OH. An alcohol (wherein R ₁ is an organic group having 1 to 18 carbon atoms) or water to open the maleic anhydride site of the structural unit represented by the formula (1a), and into the precursor polymer Step of generating a carboxyl group or a salt thereof (iii) Step of reacting a precursor polymer having a ring opening of a maleic anhydride site with a compound having an epoxy group represented by the formula (3)

(In Formula (3), R ₂ is an organic group having 2 to 18 carbon atoms, and has a carbon-carbon double bond in its structure.)

Hereinafter, each process will be described.

((I) Process)
In this step, a precursor polymer containing the structural unit represented by the above formula (1a) is prepared. Here, the structural unit represented by the formula (1a) is derived by polymerizing maleic anhydride, but in this polymerization, other monomers other than maleic anhydride can be copolymerized.

In carrying out this copolymerization, a compound having an ethylenic double bond in the molecule can be used as another monomer. Here, the ethylenic double bond includes an allyl group, an acrylic group, a methacryl group, a maleimide group, an aromatic vinyl group such as a styryl group and an indenyl group, and the like.

More specific examples of other monomers include alicyclic monomers such as norbornene; styrene monomers such as styrene, vinyltoluene, and α-methylstyrene; fluorine-containing compounds such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride. Vinyl monomers; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; nitrile group-containing vinyl monomers such as acrylonitrile and methacrylonitrile; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl acetate; Vinyl esters such as vinyl propionate, vinyl pivalate, vinyl benzoate, and vinyl cinnamate; alkenes such as ethylene and propylene; conjugated dienes such as butadiene and isoprene; vinyl chloride, vinylidene chloride, and vinyl chloride Le, it is possible to use a compound such as allyl alcohol.
Among such compounds, in the present embodiment, it is preferable to use a norbornene-type monomer represented by the following formula (2a).

(In the formula (2a), R ₃ , R ₄ , R ₅ and R ₆ are each independently hydrogen or an organic group having 1 to 30 carbon atoms. N is 0, 1 or 2.)

The organic group having 1 to 30 carbon atoms constituting R ₃ , R ₄ , R ₅ and R ₆ in the formula (2a) is one or more selected from O, N, S, P and Si in the structure May be included. Moreover, the organic group which comprises R < ₃ >, R < ₄ >, R < ₅ >, R < ₆ > does not have any acidic functional group. Thereby, control of the acid value in the polymer finally obtained can be facilitated.

In this embodiment, examples of the organic group constituting R ₃ , R ₄ , R ₅ and R ₆ include an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkaryl group, a cycloalkyl group, And heterocyclic groups.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, An octyl group, a nonyl group, and a decyl group are mentioned. Examples of the alkenyl group include allyl group, pentenyl group, and vinyl group. An ethynyl group is mentioned as an alkynyl group. Examples of the alkylidene group include a methylidene group and an ethylidene group. Examples of the aryl group include a phenyl group, a naphthyl group, and an anthracenyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the alkaryl group include a tolyl group and a xylyl group. Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of the heterocyclic group include an epoxy group and an oxetanyl group.

Furthermore, in the alkyl group, alkenyl group, alkynyl group, alkylidene group, aryl group, aralkyl group, alkaryl group, cycloalkyl group, and heterocyclic group described above, one or more hydrogen atoms may be substituted with halogen atoms. Good. Examples of the halogen atom include fluorine, chlorine, bromine and iodine. Especially, the case where the 1 or more hydrogen atom of an alkyl group is the haloalkyl group substituted by the halogen atom can be mentioned as an example of a preferable aspect. Thus, when at least one of R ₃ , R ₄ , R ₅ , and R ₆ is a haloalkyl group, a cured film is formed using the finally obtained polymer. The dielectric constant can be reduced. In addition, by using a haloalkyl alcohol group, not only the solubility in an alkali developer can be adjusted to an appropriate range, but also the heat discoloration can be improved.
In addition, from the viewpoint of increasing the light transmittance of the film that includes the finally obtained polymer, it is preferable that any or all of R ₃ , R ₄ , R ₅ , and R ₆ are hydrogen.

Specific examples of the norbornene-type monomer represented by the formula (2a) include bicyclo [2.2.1] -hept-2-ene (common name: 2-norbornene), which further has an alkyl group. As those having an alkenyl group, such as 5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, etc. Are those having an alkynyl group, such as 5-allyl-2-norbornene, 5- (2-propenyl) -2-norbornene, 5- (1-methyl-4-pentenyl) -2-norbornene, and the like, Examples of those having an aralkyl group such as -2-norbornene include 5-benzyl-2-norbornene and 5-phenethyl-2-norbol Such as emissions, and the like.
Any one or more of these can be used as the norbornene-type monomer. Among these, from the viewpoint of light transmittance of the finally obtained polymer, it is preferable to use bicyclo [2.2.1] -hept-2-ene (common name: 2-norbornene).

In this step, when the monomer represented by the above formula (2a) is used, the precursor polymer and the final product polymer include a structural unit represented by the following formula (2).

(In Formula (2), R ₃ , R ₄ , R ₅ and R ₆ are each independently hydrogen or an organic group having 1 to 30 carbon atoms. N is 0, 1 or 2.)

Hereinafter, the specific procedure of this step will be described with reference to an embodiment in which a precursor polymer is obtained using a norbornene-type monomer represented by the formula (2a) and maleic anhydride.

That is, in this step, the norbornene type monomer represented by the formula (2a) and maleic anhydride are subjected to addition polymerization. Here, for example, a copolymer (copolymer 1) of the norbornene type monomer represented by the formula (2a) and maleic anhydride is formed by radical polymerization.
By this addition polymerization, the structural unit represented by the above formula (1a) derived from maleic anhydride can be included in the precursor polymer.

The molar ratio of the norbornene-type monomer represented by the formula (2a) to maleic anhydride (mole number of the compound represented by formula (2a): mole number of maleic anhydride) is 0.5: 1 to 1: 0. .5 is preferable. Among these, from the viewpoint of controlling the molecular structure, it is more preferable that the number of moles of the norbornene-type monomer represented by the formula (2a): number of moles of maleic anhydride = 0.8: 1 to 1: 0.8.
In addition, in this addition polymerization, a monomer that can be copolymerized in addition to the above-described norbornene-type monomer and maleic anhydride can be added. Examples of such a monomer include compounds containing a group having an ethylenic double bond in the molecule. Here, specific examples of the group having an ethylenic double bond include an allyl group, an acrylic group, a methacryl group, a maleimide group, and an aromatic vinyl group such as a styryl group and an indenyl group.
In addition, the content rate of the structural unit shown by Formula (1a) in the whole precursor polymer obtained at this process is 20 mol% or more, for example, It is preferable that it is 25 mol% or more, It is 30 mol% or more. It is more preferable.
Moreover, the content rate of the structural unit shown by Formula (1a) in the whole precursor polymer obtained at this process is 80 mol% or less, for example, it is preferable that it is 75 mol% or less, and it is 70 mol% or less. It is more preferable.
The content ratio of the structural unit can be calculated from, for example, the amount of monomer charged, or can be calculated by performing NMR (nuclear magnetic resonance) analysis on the obtained precursor polymer.

As the polymerization method, for example, a polymerization method using a radical polymerization initiator and, if necessary, a molecular weight adjusting agent is suitable. In this case, methods such as suspension polymerization, solution polymerization, dispersion polymerization, and emulsion polymerization can be employed. Among these, solution polymerization is preferable. In solution polymerization, all the monomers may be charged all at once, or a part of the monomers may be charged into a reaction vessel and the rest may be dropped.

For example, the norbornene-type monomer represented by the formula (2a), the maleic anhydride, and the radical polymerization initiator are dissolved in a solvent, and then heated for a predetermined time, whereby the norbornene-type monomer represented by the formula (2a) And solution polymerization with maleic anhydride. The heating temperature is, for example, 50 to 80 ° C., and the heating time is 10 to 20 hours.

The solvent used for the polymerization can be appropriately selected as long as it does not inhibit the addition polymerization. In the present embodiment, for example, any one or more of diethyl ether, tetrahydrofuran, toluene, methyl ethyl ketone, ethyl acetate, and the like can be used as a highly versatile solvent.

As the radical polymerization initiator, any one or more of an azo compound and a peroxide can be used.
Examples of the azo compound include azobisisobutyronitrile (AIBN), dimethyl 2,2′-azobis (2-methylpropionate), 1,1′-azobis (cyclohexanecarbonitrile) (ABCN), Any one or more of these can be used.
Examples of the peroxide include hydrogen peroxide, ditertiary butyl peroxide (DTBP), benzoyl peroxide (benzoyl peroxide, BPO), and methyl ethyl ketone peroxide (MEKP). Among these, Any one or more of them can be used.

The amount (number of moles) of the radical polymerization initiator is 0.05% to the total number of moles of each monomer (for example, the sum of the number of moles of the norbornene-type monomer represented by the formula (2a) and the number of moles of maleic anhydride). 5% is preferable. It is possible to adjust the weight average molecular weight (Mw) of the obtained precursor polymer to an appropriate range by appropriately setting the amount of the radical polymerization initiator within the above range and appropriately setting the reaction temperature and reaction time. it can.

By this step, a precursor polymer (copolymer 1) having the structural unit represented by the above formula (1a) and the structural unit represented by the formula (2) can be obtained. The structural unit represented by the formula (1a) and the structural unit represented by the formula (2) may be randomly arranged, or may be alternately arranged. Moreover, the norbornene-type monomer represented by the formula (2a) and maleic anhydride may be block copolymerized. However, from the viewpoint of ensuring the uniformity of solubility of the resin composition using the polymer produced in the present embodiment, the precursor polymer is represented by the structural unit represented by the formula (1a) and the formula (2). A structure in which the structural units shown are alternately arranged is preferable. That is, the precursor polymer (copolymer 1) preferably has a structural unit represented by the following formula (4).

(In the formula (4), n and R ₃ to R ₆ are the same as those in the above formula (2). That is, n is 0, 1, or 2, and R ₃ to R ₆ are hydrogen or (It is an organic group having 1 to 30 carbon atoms. R ₃ to R ₆ may be the same or different, and a is an integer of 10 or more and 200 or less.)

In the molecular weight distribution curve obtained by, for example, GPC (Gel Permeation Chromatography), the precursor polymer (copolymer 1) in the present embodiment preferably has a peak area of 1% or less of the total molecular weight of 1000 or less.
Thus, by setting the ratio of the peak area at a molecular weight of 1000 or less in the molecular weight distribution curve obtained by GPC within the above range, the pattern shape of the film made of the resin composition containing the polymer finally obtained is good. can do.
In addition, the minimum of the quantity of the low molecular weight component in a precursor polymer (copolymer 1) is not specifically limited. However, the precursor polymer (copolymer 1) in the present embodiment allows a case where the peak area at a molecular weight of 1000 or less is 0.01% or more of the whole in a molecular weight distribution curve obtained by GPC.

In the precursor polymer in the present embodiment, for example, Mw (weight average molecular weight) / Mn (number average molecular weight) is 1.5 or more and 5.0 or less. Mw / Mn is a degree of dispersion indicating the width of the molecular weight distribution.
Thus, by controlling the molecular weight distribution in the precursor polymer to a certain range, it is possible to suppress the deformation of the pattern during curing of the film formed from the finally obtained polymer. Therefore, by setting Mw / Mn of the precursor polymer in the above range, the shape of the film made of the resin composition containing the polymer that is the final product can be improved. Such an effect is particularly noticeable when the low molecular weight component of the precursor polymer is simultaneously reduced as described above.

Moreover, Mw (weight average molecular weight) of the precursor polymer of the present embodiment is, for example, 2500 or more, preferably 3000 or more, and more preferably 4000 or more.
On the other hand, the Mw (weight average molecular weight) of the precursor polymer of this embodiment is, for example, 35000 or less, preferably 32000 or less, and more preferably 30000 or less.

In the present specification, the weight average molecular weight (Mw), the number average molecular weight (Mn), and the molecular weight distribution (Mw / Mn) are polystyrene determined from, for example, a standard polystyrene (PS) calibration curve obtained by GPC measurement. Use the converted value. The measurement conditions are, for example, as follows.
Tosoh gel permeation chromatography device HLC-8320GPC
Column: Tosoh TSK-GEL Supermultipore HZ-M
Detector: RI detector for liquid chromatogram Measurement temperature: 40 ° C
Solvent: THF
Sample concentration: 2.0 mg / milliliter In addition, the amount of low molecular weight components in the polymer is based on the data on the molecular weight obtained by GPC measurement, for example. It is calculated from the ratio.

(Step (ii))
Subsequently, an alcohol represented by R ₁ —OH (provided that R ₁ is an organic group having 1 to 18 carbon atoms) or water is allowed to act on the precursor polymer, and the above formula (1a) The maleic anhydride site of the structural unit represented by is opened to produce a carboxyl group or a salt thereof in the precursor polymer.

In this step, when alcohol is allowed to act, for example, a structural unit represented by the following formula (1b) is generated in the precursor polymer.

(In the formula (1b), R ₁ is an organic group having 1 to 18 carbon atoms.)

In the structural unit represented by the formula (1b), R ₁ is an organic group having 1 to 18 carbon atoms.
Examples of the organic group include an alkyl group, an alkenyl group, an alkynyl group, an alkylidene group, an aryl group, an aralkyl group, an alkaryl group, and a cycloalkyl group.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, An octyl group, a nonyl group, and a decyl group are mentioned. Examples of the alkenyl group include allyl group, pentenyl group, and vinyl group. An ethynyl group is mentioned as an alkynyl group. Examples of the alkylidene group include a methylidene group and an ethylidene group. Examples of the aryl group include a phenyl group, a naphthyl group, and an anthracenyl group. Examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the alkaryl group include a tolyl group and a xylyl group. Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

Here, the polymer finally obtained in the present embodiment can be used, for example, as a polymer constituting the negative photosensitive resin composition, but when applied to the negative photosensitive resin composition in this way, In addition to R ₂ described in detail later, R ₁ also preferably has a radical polymerizable group that initiates radical polymerization by a photoradical generator. More specifically, R ₁ preferably has a carbon-carbon double bond in its structure, and includes any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group, and a methacryloyl group. It is more preferable. R ₁ is more preferably any of the following formulas (I) and (II).

(In formula (I), f is an integer of 1 to 5, and in formula (II), e is an integer of 1 to 9.)

Incidentally, R ₁ is is preferably the same in a plurality of repeating units represented by the formula (1b), may be different for each repeating unit of the formula (1b).

Further, as R ₁ , an organic group having 8 to 18 carbon atoms including an aromatic ring may be used. In this case, for example, a vinylaryl group (—Ar—CH═CH ₂ , Ar represents an aromatic hydrocarbon group) can be employed as R ₁ .

In addition, the organic group having 1 to 18 carbon atoms constituting R ₁ in formula (1b) may contain one or more atoms of O, N, S, P, and Si in the structure. Further, the organic group constituting R ₁ may not contain an acidic functional group. Thereby, control of the acid value in the polymer finally obtained can be facilitated.

In addition, about the precursor polymer converted at this process, the structural unit shown by this Formula (1b) and the structural unit shown by Formula (1c) mentioned later may contain the salt.

In addition to the above-described embodiment using alcohol, when water is allowed to act on the precursor polymer, a structural unit represented by the following formula (1c) is generated in the precursor polymer.

In this step, the structural unit represented by the formula (1a) in the precursor polymer is represented by the structural unit represented by the above formula (1b) or (1c), or these formula (1b) and formula (1c). To a structural unit salt. Here, the conversion rate represented by the following formula is set to, for example, 5% or more, preferably 10% or more, and more preferably 20% or more.
On the other hand, the upper limit value of the conversion rate represented by the following equation is not particularly limited, but is, for example, 99.9% or less.
Conversion rate (%) = 100 × [(number of moles of structural unit and salt thereof represented by formula (1b) after this step) + (of structural unit and salt thereof represented by formula (1c) after this step) Number of moles)] / [number of moles of structural unit represented by formula (1a) before this step)]

This step can be performed, for example, by adding a predetermined amount of alcohol or water to the solution containing the precursor polymer having the structural unit represented by the formula (1a) and heating.
The solvent that dissolves the precursor polymer can be appropriately selected from those that do not inhibit the reaction, and the heating conditions can be set in the range of 50 to 100 ° C., for example. The reaction time can be appropriately set while observing the degree of change in the chemical structure of the polymer.
As the solvent used in this step, for example, one or more of diethyl ether, tetrahydrofuran, toluene, methyl ethyl ketone, ethyl acetate and the like can be used as a highly versatile solvent.

In this heating, a catalyst can be appropriately added from the viewpoint of promoting the reaction, and for example, a base catalyst or an acid catalyst can be added.
As the base catalyst, pyridine, alkylamines such as triethylamine, amine compounds such as dimethylaniline, urotropine and dimethylaminopyridine, and metal salts such as sodium acetate can be used.
As the acid catalyst, mineral acids such as sulfuric acid and hydrochloric acid, organic acids such as paratoluenesulfonic acid, Lewis acids such as boron trifluoride etherate, and the like can be used.
In addition, when using a base catalyst at this process, this base and the produced | generated carboxyl group may form a salt (carboxylate). In this case, it is possible to proceed to the next step while maintaining the structure of this carboxylate salt, or to react with an acid such as hydrochloric acid or formic acid so as to be represented by the above formula (1b) or formula (1c). Further, it can be converted into a structural unit having a carboxyl group at the terminal.

((Iii) step)
In this step, the precursor polymer obtained by opening the maleic anhydride moiety obtained in the previous step is reacted with a compound having an epoxy group represented by formula (3).

(In Formula (3), R ₂ is an organic group having 2 to 18 carbon atoms, and has a carbon-carbon double bond in its structure.)

As a more specific aspect of this step, a solution containing a precursor polymer containing the structural unit (or a salt thereof) represented by the above formula (1b) or (1c), and a compound represented by the formula (3) And are heated.
The solvent that dissolves the precursor polymer can be appropriately selected from those that do not inhibit the reaction, and the heating conditions can be set in the range of 50 to 100 ° C., for example. The reaction time can be appropriately set while observing the degree of change in the chemical structure of the polymer.

The compound represented by formula (3) can be appropriately selected from those with a specific R _2.
Specifically, R ₂ is an organic group having 2 to 18 carbon atoms and has a carbon-carbon double bond in its structure. Examples of R ₂ include an allyl group, a pentenyl group, And an organic group containing an alkenyl group such as a vinyl group. More specifically, R ₂ preferably includes any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group, and a methacryloyl group, and more preferably includes an acryloyl group or a methacryloyl group.
In addition, as R ₂ , any of the groups of formula (I) and formula (II) described above can be adopted.

R ₂ is preferably the same for each structural unit to be formed, but may be different for each structural unit to be formed.
Further, as R ₂ , an organic group having 8 to 18 carbon atoms including an aromatic ring may be used. In this case, for example, a vinylaryl group (—Ar—CH═CH ₂ , Ar represents an aromatic hydrocarbon group) can be employed as R ₂ .

Further, the organic group having 2 to 18 carbon atoms constituting R ₂ may contain one or more atoms of O, N, S, P and Si in the structure. The organic group constituting R ₂ may be made free of acid functionality. Thereby, control of the acid value in the polymer obtained can be facilitated.

In this embodiment, it is preferable to use glycidyl acrylate or glycidyl methacrylate as the compound represented by the formula (3) in view of high availability.

Here, when the compound represented by the formula (3) is allowed to act on the structural unit represented by the formula (1b), the structural unit represented by the formula (1b) is represented by the formula (1). Can be converted to a structural unit.
That is, the polymer obtained by the present embodiment can include a structural unit represented by the formula (1).

(In Formula (1), R ₁ is an organic group having 1 to 18 carbon atoms. R ₂ is an organic group having 2 to 18 carbon atoms, and has a carbon-carbon double bond in the structure thereof.)

On the other hand, when the compound represented by the formula (3) is allowed to act on the structural unit represented by the formula (1c), the structural unit represented by the formula (1c) is represented by the formula (1d). Can be converted to a structural unit.
In the present embodiment, the structural unit represented by the formula (1d) preferably corresponds to the structural unit represented by the formula (1).

(In the formula (1d), each R ₂ is an organic group having 2 to 18 carbon atoms and has a carbon-carbon double bond in its structure.)

In this step, a catalyst can be appropriately added from the viewpoint of promoting the reaction, and for example, a base catalyst or an acid catalyst can be added.
As the base catalyst, pyridine, alkylamines such as triethylamine, amine compounds such as dimethylaniline, urotropine and dimethylaminopyridine, and metal salts such as sodium acetate can be used.
As the acid catalyst, mineral acids such as sulfuric acid and hydrochloric acid, organic acids such as p-toluenesulfonic acid, Lewis acids such as boron fluoride etherate, and the like can be used.
When a base catalyst is used in this step, since this base and the carboxyl group in the polymer may form a salt (carboxylate), an acid such as hydrochloric acid or formic acid is allowed to act, It is preferable to convert the carboxylate moiety to a carboxyl group.

As described above, the polymer of the present embodiment can be produced. However, in the polymer production method of the present embodiment, a process of washing the precursor polymer may be interposed between the steps, In addition, when a structural unit other than the structural unit derived from maleic anhydride or the compound represented by formula (2a) is included, a treatment suitable for converting the structural unit may be interposed between the steps. Good.

The polymer obtained by the present embodiment may contain a structural unit derived from maleic anhydride represented by the above formula (1). In addition to this structural unit, the structural unit represented by the following formula (1b) And a structural unit represented by the formula (1c).
These structural units have a carboxyl group and impart alkali solubility as a polymer.

(In the formula (1b), R ₁ is the same as R ₁ described above.)

In addition, the alkali dissolution rate of the polymer obtained by the present embodiment is, for example, not less than 500 kg / sec and not more than 30000 kg / sec. The alkali dissolution rate of the polymer can be determined by, for example, dissolving a polymer in propylene glycol monomethyl ether acetate and applying a polymer solution adjusted to a solid content of 20% by weight on a silicon wafer by a spin method, followed by soft baking at 110 ° C. for 100 seconds. The polymer film thus obtained is impregnated with a 2.38% tetramethylammonium hydroxide aqueous solution at 23 ° C., and the time until the polymer film is visually erased is calculated.
By setting the alkali dissolution rate of the polymer to 500 kg / second or more, it is possible to improve the throughput in the development step using an alkali developer. Moreover, the residual film rate after the image development process by an alkali developing solution can be improved by making the alkali dissolution rate of a polymer into 30000 kg / sec or less. For this reason, it is possible to suppress film loss due to the lithography process.
From the same viewpoint, the alkali dissolution rate of the polymer is more preferably 1000 kg / sec or more, and further preferably 2000 kg / sec or more. The alkali dissolution rate of the polymer is more preferably 28000 kg / second or less, and further preferably 25000 kg / second or less.

In the molecular weight distribution curve obtained by GPC (Gel Permeation Chromatography), for example, the peak area at a molecular weight of 1000 or less is preferably 1% or less of the polymer obtained by the present embodiment.
Thus, by setting the ratio of the peak area at a molecular weight of 1000 or less in the molecular weight distribution curve obtained by GPC within the above range, the pattern shape of the film made of the resin composition containing this polymer can be improved. .
In addition, the minimum of the quantity of the low molecular weight component in the polymer obtained by this embodiment is not specifically limited. However, the polymer in the present embodiment allows a case where the peak area at a molecular weight of 1000 or less is 0.01% or more of the entire molecular weight distribution curve obtained by GPC.

The polymer obtained by this embodiment has, for example, Mw (weight average molecular weight) / Mn (number average molecular weight) of 1.5 or more and 5.0 or less.
As described above, by controlling the molecular weight distribution in the polymer within a certain range, it is possible to suppress the deformation of the pattern at the time of curing of the film formed by the polymer obtained according to the present embodiment. Therefore, when the Mw / Mn of the polymer is in the above range, the shape of the film made of the resin composition containing the polymer can be improved.

Moreover, Mw (weight average molecular weight) of the polymer obtained by the present embodiment is, for example, 2500 or more, preferably 3000 or more, and more preferably 4000 or more.
On the other hand, the Mw (weight average molecular weight) of the polymer obtained by the present embodiment is, for example, 35000 or less, preferably 32000 or less, and more preferably 30000 or less.
By setting Mw (weight average molecular weight) in such a range, the polymer of the present embodiment is appropriately dissolved in a solvent when forming a negative photosensitive resin composition, and constitutes a resin film. In this case, appropriate rigidity can be exhibited.

The polymer obtained by this embodiment can be preferably used for forming a photosensitive resin film because of the specificity of the chemical performance contained in this structural unit.
In the present specification, the “photosensitive resin film” refers to a resin film that is subjected to an exposure process in the manufacturing process of an electronic device or the like. More specifically, the “photosensitive resin film” is a negative type in which a portion irradiated with light is cured, and a portion not irradiated is dissolved and removed in a developing solution (for example, an alkaline solution) in a development process. The photosensitive resin film.

[Negative photosensitive resin composition]
Then, the negative photosensitive resin composition concerning this embodiment is demonstrated.
The negative photosensitive resin composition according to this embodiment is obtained by blending a polymer obtained by the production method described above and a photoradical generator.

Specific examples of the photo radical generator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl. Propan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2 -Hydroxy-2-methylpropionyl) benzyl] phenyl} -2-methylpropan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2- Dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenol Alkyl) phenone compounds such as (l) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone; benzophenones such as benzophenone, 4,4′-bis (dimethylamino) benzophenone, 2-carboxybenzophenone Compound: Benzoin compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4 A thioxanthone compound such as diethylthioxanthone; 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) -4,6-bis ( Lichloromethyl) -s-triazine, 2- (4-ethoxynaphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-ethoxycarboquinylnaphthyl) -4,6-bis (trichloromethyl) Halomethylated triazine compounds such as —s-triazine; 2-trichloromethyl-5- (2′-benzofuryl) -1,3,4-oxadiazole, 2-trichloromethyl-5- [β- (2′- Benzofuryl) vinyl] -1,3,4-oxadiazole, 4-oxadiazole, 2-trichloromethyl-5-furyl-1,3,4-oxadiazole and the like halomethylated oxadiazole compounds; 2 , 2'-bis (2-chlorophenyl) -4,4 ', 5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis (2,4-dichlorophenyl) Nyl) -4,4 ′, 5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis (2,4,6-trichlorophenyl) -4,4 ′, 5,5 ′ -Biimidazole compounds such as tetraphenyl-1,2'-biimidazole; 1,2-octanedione, 1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone, 1- [9 Oxime ester compounds such as -ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime); bis (η5-2,4-cyclopentadiene-1- Yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium and the like; benzoic acid esters such as p-dimethylaminobenzoic acid and p-diethylaminobenzoic acid Compounds; acridine compounds such as 9-phenylacridine; and the like.

In the negative photosensitive resin composition of the present embodiment, the photoradical generator is preferably 1 part by mass or more and 20 parts by mass or less, more preferably 2 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the whole polymer. The following is preferable.

Further, by using a photosensitizer or a photoradical polymerization accelerator together with the photoradical generator, the sensitivity and the degree of crosslinking can be further improved. For example, dye compounds such as xanthene dyes and coumarin dyes, dialkylaminobenzene compounds such as ethyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-dimethylaminobenzoate, 2-mercaptobenzothiazole, 2-mercaptobenzoimidazole, etc. And mercapto-type hydrogen donors.

(solvent)
The negative photosensitive resin composition described in this embodiment can be used as a varnish by dissolving the above-described components in a solvent.
Examples of such solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol Monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl-1,3-butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate, and ethyl and methyl pyruvate -3-Methoxypropionate and the like.
Of these compounds, γ-butyrolaclone, dimethyl sulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether are among these compounds from the viewpoint of significantly suppressing the occurrence of cracks in the resin film. It is preferable to use a compound selected from the group consisting of propylene glycol monomethyl ether acetate.

Although content of the solvent in the negative photosensitive resin composition of this embodiment is not specifically limited, It is preferable that it is 100 mass parts or more with respect to 100 mass parts of polymers, and is 150 mass parts or more. More preferably.
Moreover, it is preferable that it is 1000 mass parts or less with respect to 100 mass parts of polymers, and, as for content of the solvent in the negative photosensitive resin composition of this embodiment, it is more preferable that it is 800 mass parts or less. When the content of the solvent is within the above range, an appropriate handling property can be provided.

Further, the negative photosensitive resin composition of the present embodiment includes a filler, a binder resin other than the aforementioned polymer, a crosslinking agent, an acid generator, a heat improver, and a development aid depending on the purpose and required characteristics of each application. , Plasticizer, polymerization inhibitor, UV absorber, antioxidant, matting agent, antifoaming agent, leveling agent, antistatic agent, dispersant, slip agent, surface modifier, thixotropic agent, thixotropic agent Components other than the above essential components such as surfactants, silane-based, aluminum-based, titanium-based coupling agents, and polyhydric phenol compounds may be blended.

[Colored photosensitive resin composition]
The negative photosensitive resin composition of this embodiment can be made into a colored photosensitive resin composition by further including a colorant.
Such a colored photosensitive resin composition can be suitably used, for example, when producing a black matrix or a colored pattern constituting a color filter.

The colored photosensitive resin composition of the present embodiment contains a conventionally known pigment or dye.
As the pigment, an organic pigment or an inorganic pigment can be used.
Organic pigments include azo pigments, phthalocyanine pigments, polycyclic pigments (quinacridone, perylene, perinone, isoindolinone, isoindoline, dioxazine, thioindigo, anthraquinone, quinophthalone, metal complex System, diketopyrrolopyrrole, etc.), dye lake pigments, etc. can be used.
Inorganic pigments include white and extender pigments (titanium oxide, zinc oxide, zinc sulfide, clay, talc, barium sulfate, calcium carbonate, etc.) and chromatic pigments (yellow lead, cadmium, chrome vermilion, nickel titanium, chrome titanium) , Yellow iron oxide, bengara, zinc chromate, red lead, ultramarine, bitumen, cobalt blue, chromium green, chromium oxide, bismuth vanadate, etc.), black pigment (carbon black, bone black, graphite, iron black, titanium black, etc.) Bright pigments (pearl pigments, aluminum pigments, bronze pigments, etc.) and fluorescent pigments (zinc sulfide, strontium sulfide, strontium aluminate, etc.) can be used.

The pigment colors that can be used include yellow, red, purple, blue, green, brown, black, and white.

As the dye, for example, known dyes (compounds) described in JP-A No. 2003-270428, JP-A No. 9-171108, JP-A No. 2008-50599 and the like can be used.

The above colorants can be used alone or in combination of two or more. As the above-mentioned colorant, those having an appropriate average particle diameter can be used according to the purpose and application. However, when transparency such as a color resist for color filters is required, it is as small as 0.1 μm or less. An average particle diameter is preferable, and when a concealing property such as a paint is required, a large average particle diameter of 0.5 μm or more is preferable. In addition, the above-described coloring material is subjected to surface treatment such as rosin treatment, surfactant treatment, resin dispersant treatment, pigment derivative treatment, oxide film treatment, silica coating, wax coating, etc., depending on the purpose and application. Also good.

The content ratio of the colorant in the colored photosensitive resin composition of the present embodiment may be appropriately set according to the purpose and application. From the viewpoint of balancing coloring power and dispersion stability, the colored photosensitive resin composition When the total solid content of the product (that is, the component excluding the solvent) is 100 parts by mass, it is preferably 3% by mass to 70% by mass, more preferably 5% by mass to 60% by mass, and still more preferably 10%. It is not less than 50% by mass.

[Usage]
The negative photosensitive resin composition of this embodiment can obtain a resin film by using a cured product.
Such a resin film can be used, for example, as a resist, and can also constitute a permanent film such as a protective film, an interlayer film, or a dam material.

Next, an example of the electronic device 100 to which the negative photosensitive resin composition of the present embodiment is applied will be described.
An electronic device 100 shown in FIG. 1 is, for example, a semiconductor chip. In this case, for example, a semiconductor package can be obtained by mounting the electronic device 100 on the wiring board via the bumps 52. The electronic device 100 includes a semiconductor substrate provided with a semiconductor element such as a transistor, and a multilayer wiring layer provided on the semiconductor substrate (not shown). An interlayer insulating film 30 and an uppermost layer wiring 34 provided on the interlayer insulating film 30 are provided in the uppermost layer of the multilayer wiring layer. The uppermost layer wiring 34 is made of, for example, Al. Further, a passivation film 32 is provided on the interlayer insulating film 30 and the uppermost layer wiring 34. An opening through which the uppermost layer wiring 34 is exposed is provided in a part of the passivation film 32.

A rewiring layer 40 is provided on the passivation film 32. The rewiring layer 40 includes an insulating layer 42 provided on the passivation film 32, a rewiring 46 provided on the insulating layer 42, an insulating layer 44 provided on the insulating layer 42 and the rewiring 46, Have An opening connected to the uppermost layer wiring 34 is formed in the insulating layer 42. The rewiring 46 is formed on the insulating layer 42 and in an opening provided in the insulating layer 42, and is connected to the uppermost layer wiring 34. The insulating layer 44 is provided with an opening connected to the rewiring 46.
In the present embodiment, one or more of the passivation film 32, the insulating layer 42, and the insulating layer 44 may be formed of a resin film formed by curing, for example, the above-described negative photosensitive resin composition. it can. In this case, for example, the coating film formed of the negative photosensitive resin composition is exposed to ultraviolet rays, developed and patterned, and then heat-cured to thereby passivate the passivation film 32, the insulating layer 42, or the insulating film. Layer 44 is formed.

In the opening provided in the insulating layer 44, for example, a bump 52 is formed via a UBM (Under Bump Metallurgy) layer 50. The electronic device 100 is connected to a wiring board or the like via bumps 52, for example.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention.

Next, examples of the present invention will be described.

(Example 1: Polymer synthesis)
In an appropriately sized reaction vessel equipped with a stirrer and a condenser, maleic anhydride (Nippon Shokubai Co., Ltd., 122.4 g, 1.25 mol), 2-norbornene (75 wt% toluene solution, manufactured by Maruzen Petrochemical Co., Ltd.) 156.8 g, 1.25 mol) and dimethyl 2,2′-azobis (2-methylpropionate) (V-601, manufactured by Wako Pure Chemical Industries, Ltd., 11.5 g, 50 mmol) were weighed and methyl ethyl ketone ( MEK, 150.8 g) and toluene (38.5 g).
The solution was purged with nitrogen for 10 minutes to remove oxygen, and then heated to 60 ° C. with stirring. After 16 hours, MEK (320 g) was added to dilute and cool.
This reaction mixture was dropped into a large amount of methanol to precipitate a polymer. After filtration using a Nutsche, it was further washed with methanol and the solid was collected by filtration. The resulting polymer was vacuum dried at 70 ° C. The yield was 208.1 g, the weight average molecular weight (Mw) was 11,100, and the degree of dispersion (Mw / Mn) was 2.25 (referred to as “precursor polymer” in this Example section).
Subsequently, the above-mentioned precursor polymer (10.0 g) was weighed and dissolved in MEK (30.0 g) in an appropriately sized reaction vessel equipped with a stirrer and a cooling pipe. Further, 2-hydroxyethyl methacrylate (HEMA, Nippon Shokubai Co., Ltd., 8.5 g, 65 mmol) and sodium acetate (1.0 g) were added and heated at 70 ° C. for 8 hours.
To this reaction solution, glycidyl methacrylate (GMA, 3.7 g, 26 mmol) was added, and the mixture was further stirred at 70 ° C. for 16 hours. After formic acid was added to the reaction solution for acid treatment, it was dropped into a large amount of pure water to precipitate a polymer. The solid collected by filtration was dried in a vacuum dryer at 40 ° C. for 16 hours to obtain 13.8 g of a pale yellow solid.
The physical properties of the obtained polymer are as follows.
Weight average molecular weight (Mw): 16,200
Dispersity: 2.46

(Example 2: Polymer synthesis)
Into a suitably sized reaction vessel equipped with a stirrer and condenser, maleic anhydride (735 g, 7.5 mol), 2-norbornene (706 g, 7.5 mol) and dimethyl 2,2′-azobis (2-methylpro) Pionate) (69 g, 0.3 mol) was weighed and dissolved in methyl ethyl ketone (900 g) and toluene (231 g).
After removing dissolved oxygen in the system by nitrogen bubbling, this solution was heat-treated at 60 ° C. for 15 hours with stirring. As a result, a copolymer of 2-norbornene and maleic anhydride was obtained. Subsequently, after re-precipitating the said melt | dissolution solution cooled to room temperature using a lot of methanol, the deposit was filtered and dried with the vacuum dryer, and 1100g of white solid was obtained.
This white solid (10 g) was mixed with 10% sodium hydroxide solution (40 g) and stirred at 70 ° C. for 16 hours. After cooling to room temperature, it was reprecipitated in 400 g of 5% aqueous hydrochloric acid solution, and then thoroughly washed with pure water. The dicarboxylic acid body (8g) was obtained by making it dry with a vacuum dryer.
The dicarboxylic acid compound (3.0 g) thus obtained was dissolved in THF (12 g), mixed with glycidyl methacrylate (4.0 g) and triethylamine (0.1 g), and reacted at 70 ° C. for 12 hours. After the reaction solution was reprecipitated in heptane, the precipitate was collected by filtration and dried in a vacuum dryer to obtain 4.3 g of a white solid.
The physical properties of the obtained polymer are as follows.
Weight average molecular weight (Mw): 13,600
-Dispersity: 2.22

(Comparative Example 1: Polymer synthesis carried out without using a compound having an epoxy group)
The precursor polymer (10.0 g) described in Example 1 was weighed into a suitably sized reaction vessel equipped with a stirrer and a condenser, and dissolved in MEK (30.0 g). Further, 2-hydroxyethyl methacrylate (8.5 g, 65 mmol) and sodium acetate (1.0 g) were added, and the mixture was heated at 70 ° C. for 24 hours. After formic acid was added to the reaction solution for acid treatment, it was dropped into a large amount of pure water to precipitate a polymer. The solid collected by filtration was dried in a vacuum dryer at 40 ° C. for 16 hours to obtain 11.2 g of a polymer.
The physical properties of the obtained polymer are as follows.
Weight average molecular weight (Mw): 12,400
・ Dispersity: 2.16

[Preparation of negative photosensitive resin composition]
For each 2.0 g of the polymers obtained in Examples and Comparative Examples, 1.0 g of dipentaerythritol hexaacrylate (A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd.), which is a cross-linking agent, and the following formula (10) 0.1 g of a photo radical generator (IRGACURE OXE02 (manufactured by BASF)), silane coupling agent (KBM-403 (3-glycidoxypropyltrimethoxysilane; manufactured by Shin-Etsu Chemical Co., Ltd.)) 02 g and 0.01 g of a surfactant (F556 (manufactured by DIC Corporation)) were dissolved in propylene glycol monomethyl ether acetate to obtain a solution having a solid content of 30%. Thereafter, the mixture was filtered through a membrane filter having a pore size of 0.2 μm to prepare a photosensitive resin composition.
The correspondence relationship between the polymer used and the obtained negative photosensitive resin composition is as shown in Table 1.

[Evaluation]
About the obtained negative photosensitive resin composition, it evaluated according to the following.

(sensitivity)
The negative photosensitive resin composition obtained above was spin-coated on a silicon wafer (rotation speed: 500 to 3000 rpm) and baked on a hot plate at 100 ° C. for 120 seconds to obtain a thin film A of about 3 μm. The thin film A was exposed by varying the exposure amount by 5 mJ / cm ² using an exposure apparatus. As the exposure apparatus, a g + h + i line mask aligner (PLA-501F) manufactured by Canon Inc. was used.
The exposed film was developed using a TMAH developer (concentration: 2.38%) at 23 ° C. for 60 seconds and rinsed with pure water to obtain a thin film B. The exposure amount at which thin film B / thin film A × 100 ≧ 95% was defined as sensitivity (mJ / cm ² ). The results are summarized in Table 1 for this sensitivity. In contrast to Comparative Example 2, it was found that the negative photosensitive resin compositions of Examples 3 and 4 using a polymer having a specific structural unit can obtain a high residual film ratio with a lower exposure amount.

(Remaining film ratio after development)
The negative photosensitive resin composition obtained above was spin-coated on a silicon wafer (rotation speed: 500 to 3000 rpm) and baked on a hot plate at 100 ° C. for 120 seconds to obtain a thin film A of about 3 μm. The thin film A was exposed to 100 mJ / cm ² using an exposure apparatus.
The exposed film was developed using a TMAH developer (concentration: 2.38%) at 23 ° C. for 60 seconds and rinsed with pure water to obtain a thin film B. Table 1 shows (thin film B / thin film A) × 100 [%] as a remaining film ratio after development. In Comparative Example 2, an increase in film thickness was observed due to swelling of the alkaline developer, while in Examples 3 and 4, no swelling was observed.

This application claims priority based on Japanese Patent Application No. 2016-044214 filed on Mar. 8, 2016, the entire disclosure of which is incorporated herein.

Since the polymer obtained by the production method of the present invention can be cured at a low exposure, it is useful for constituting a negative photosensitive resin composition or the like.

Claims (15)

1. Preparing a precursor polymer containing a structural unit represented by the following formula (1a);
   Alcohol represented by R ₁ —OH (where R ₁ is an organic group having 1 to 18 carbon atoms) or water is allowed to act on the precursor polymer containing the structural unit represented by the formula (1a). Opening the maleic anhydride site of the structural unit represented by formula (1a) to form a carboxyl group or a salt thereof in the precursor polymer,
   Reacting a compound having an epoxy group represented by the formula (3) with the precursor polymer having a ring opening of a maleic anhydride site;
   A process for producing a polymer comprising
   

   

   

   (In Formula (3), R ₂ is an organic group having 2 to 18 carbon atoms, and has a carbon-carbon double bond in its structure.)
2. A method for producing the polymer according to claim 1, comprising:
   Production of a polymer, wherein R ₂ of the compound having an epoxy group represented by the formula (3) includes in its structure any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group, and a methacryloyl group Method.
3. A method for producing a polymer according to claim 1 or 2,
   A method for producing a polymer, wherein an alcohol having a carbon-carbon double bond in the structure of R ₁ is used in the step of generating a carboxyl group or a salt thereof in a precursor polymer.
4. A method for producing a polymer according to claim 3,
   The method for producing a polymer, wherein R ₁ includes in its structure any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group, and a methacryloyl group.
5. A method for producing a polymer according to any one of claims 1 to 4,
   The method for producing a polymer, wherein the precursor polymer further includes a structural unit represented by the following formula (2).
   

   

   (In Formula (2), R ₃ , R ₄ , R ₅ and R ₆ are each independently hydrogen or an organic group having 1 to 30 carbon atoms. N is 0, 1 or 2.)
6. A method for producing a polymer according to any one of claims 1 to 5,
   The method for producing a polymer, wherein the polymer has a weight average molecular weight (Mw) of 2500 or more and 35000 or less.
7. A method for producing a polymer according to any one of claims 1 to 6,
   The method for producing a polymer, wherein the polymer is a polymer for forming a photosensitive resin film.
8. A method for producing a negative photosensitive resin composition comprising the steps of: obtaining a polymer by the method for producing a polymer according to any one of claims 1 to 7; and further blending a photoradical generator. Method.
9. A method for producing a resin film, comprising: obtaining a negative photosensitive resin composition by the method for producing a negative photosensitive resin composition according to claim 8; and further curing the negative photosensitive resin composition. .
10. An electronic device manufacturing method comprising the resin film manufacturing method according to claim 9 in the process.
11. A polymer containing a structural unit represented by the following formula (1).
    

    

    (In Formula (1), R ₁ is an organic group having 1 to 18 carbon atoms. R ₂ is an organic group having 2 to 18 carbon atoms, and has a carbon-carbon double bond in the structure thereof.)
12. A polymer according to claim 11, comprising:
    R ₂ in the formula (1) is a polymer containing in its structure any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group, and a methacryloyl group.
13. A polymer according to claim 11 or 12,
    R ₁ in the formula (1) is a polymer having a carbon-carbon double bond in its structure.
14. A polymer according to claim 13,
    R ₁ in the formula (1) is a polymer containing in its structure any group selected from the group consisting of a vinyl group, a vinylidene group, an acryloyl group, and a methacryloyl group.
15. A polymer according to any one of claims 11 to 14, comprising
    Furthermore, the polymer containing the structural unit shown by the following formula | equation (2).
    

    

    (In Formula (2), R ₃ , R ₄ , R ₅ and R ₆ are each independently hydrogen or an organic group having 1 to 30 carbon atoms. N is 0, 1 or 2.)

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